title: Strong-field quantum control of 2 + 1 photon absorption of atomic sodium.
abstract: We demonstrate ultrafast coherent control of multiphoton absorption in a dynamically shifted energy level structure. In a three-level system that models optical interactions with sodium atoms, we control the quantum interference of sequential 2 + 1 photons and direct three-photon transitions. Dynamic change in energy levels predicts an enormous enhancement of |7p>-state excitation in the strong-field regime by a negatively chirped pulse. In addition, the |4s>-state excitation is enhanced symmetrically by nonzero linear chirp rates given as a function of laser peak intensity and laser detuning. Experiments performed by ultrafast shaped-pulse excitation of ground-state atomic sodium verifies the various strong-field contributions to |3s>-|7p> and |3s>-|4s> transitions. The result suggests that for systems of molecular level understanding adiabatic control approach with analytically shaped pulses becomes a more direct control than feedback-loop black-box approaches.
authors.affiliation: Department of Physics, KAIST, Daejeon 305-701, Korea.
authors.forename: Sangkyung
authors.initials: S
authors.lastname: Lee
authors.forename: Jongseok
authors.initials: J
authors.lastname: Lim
authors.forename: Chang Yong
authors.initials: CY
authors.lastname: Park
authors.forename: Jaewook
authors.initials: J
authors.lastname: Ahn
mesh_terms: D000042:Absorption; D003198:Computer Simulation; D008956:Models, Chemical; D017785:Photons; D011789:Quantum Theory; D012964:Sodium / Q000737:chemistry*
chemical_list: D012964:Sodium